Binding ramp angle differences

[cantunamunch]

Oh, I see, you kept the original 4mm at the toe and added 4mm at the heel.

The initial mount was with the 4mm toe shim. That's what had me close to zero delta.

 

[Erik Timmerman]

With no shims it is 4.5-5ish down at the toe. First mount was with the 4mm shim putting me about 1mm down. Remount I would have replaced the 4mm shim with a 2mm but didn't have one, so went with 6 toe and 4 heel to reach the same place.

(I say about because the heel piece is actually not flat, but is angled forward, so you get a different measure depending on where you put the caliper)

 

[eok]

I think I have a basic understanding of ramp angle & delta, but I've wondered something that I'll ask here:

For a ski with a sweet spot a little further back than you'd like (like 1.5-2cm), will adding toe lift help?

 

[bud heishman]

I think I have a basic understanding of ramp angle & delta, but I've wondered something that I'll ask here:

For a ski with a sweet spot a little further back than you'd like (like 1.5-2cm), will adding toe lift help?

If you want to make a short ski feel longer, move the mounting position back and lift the toes. If your skis are center mounted or with the sweet spot aft, adding toe lift would be counter productive because the skier must already adapt their stance to be more aft over the sweet spot so lifting the toes would really challenge balance. Consequently lifting the heel or increasing the delta angle would aid balance in this situation.

 

[eok]

Hey thanks Bud. Would an in-boot heel lift be valid for me to test this - before I commit to shimming the binding heel piece?

I know, I could probably just move the binding back 1.5cm, but that would require a complete re-mount & new holes. Ug!

 

[bud heishman]

Hey thanks Bud. Would an in-boot heel lift be valid for me to test this - before I commit to shimming the binding heel piece?

I know, I could probably just move the binding back 1.5cm, but that would require a complete re-mount & new holes. Ug!

In boot heel lift and outside boot heel lift produce two different results.

 

[eok]

In boot heel lift and outside boot heel lift produce two different results.

Ah, I understand. Thanks!

 

[updown]

In boot heel lift and outside boot heel lift produce two different results.

What are they pls?

 

[bud heishman]

What are they pls?

Think about it.... a heel lift inside the boot opens the ankle joint but does not change lower leg angle. A lift under the heel outside the boot changes the lower leg angle but does not change the net forward lean angle of the leg and foot relationship inside the boot. They have two distinctly different purposes. Ramp angle is internal, Delta angle is external.

 

[updown]

Think about it.... a heel lift inside the boot opens the ankle joint but does not change lower leg angle. A lift under the heel outside the boot changes the lower leg angle but does not change the net forward lean angle of the leg and foot relationship inside the boot. They have two distinctly different purposes. Ramp angle is internal, Delta angle is external.

Thank you, after playing with a couple of books under my feet and heels I understand. Now, 'distinct purposes'?

 

[PTskier]

I just stumbled into this old thread. I've been thinking about off-season purchases of skis & bindings. My skiing on my Head PRX bindings with their 8 mm stand height difference has me skiing my best ever. Better than on PRD with a 4 mm difference. I'll replicate that 8 mm on whatever I end up buying.

I know, it's all about me...my boot sole length, my boot ramp angle, my boot shaft angle, my lower leg vs. upper leg lengths, my total leg length vs. body length, body shape, probably a couple of other factors. If my settings are just right for anyone else, it's just coincidence.

Posting #29 makes an important point. An evidently very good skier can't do a simple movement. If it isn't technique, it must be the body dimensions related to equipment. The posts about very good skiers seamlessly adapting to their equipment set up misses the point. What about the rest of us who were not born with a big dollop of innate athleticism? We need all the help we can get. Carefully finding the correct set up (or stumbling across it..) is a huge help. I rented the skis with the PRX bindings and really liked them, so I bought some. Yep, very good skis, but how much of that liking was a better binding set up for me? I don't know. Why do some skis & bindings "work" for some skiers and "not work" for others. It's complex, and this binding set up is one important aspect.


Bud said that a good skier can feel a 1 cm forward or back binding position change. I can feel the 4 mm change on one notch on the rail of those Head/Tyrolia bindings. The '15 Supershape Rally skis much better with the bindings two notches (8 mm) forward--much better tip bite and still float good in crud. I've tried this with other skiers on Supershape i.Speed, tried one notch forward, tried two (8mm), and they put them back at one forward (4 mm). Same thing on a pair of K2s with Marker rental bindings. I'll put rail bindings on my next skis so I can experiment this way to find my sweet spot.

 

[ScottB]

I bumped into this "delta" issue a few years back. I was never aware of it so I never gave it a thought. I suspect I am like most skiers, who just use whatever gear they buy and adjust to it. I also think you don't realize what you are missing until you experience it and have it taken away.

I am a "human factors" outlier at 6'4" with 36" inseam. I am a clydesdale and I found the "limit" of when delta really begins to effect your skiing. I ski a lot on a pair of Ski Logik Chariots which are 101mm under foot and 178cm long. They are basically fat slalom skis, and I really should be on the 188cm length. I was skiing very fast on a roughed up groomer in heavy dense snow. I almost went over the handle bars several times and just couldn't find a comfortable balance point. I switched to my 193 cm FIS GS race skis and problem solved (and I could go even faster). When I got home I measured my binding delta (Marker Jesters) and found it to be about 6mm (heel high). My race skis had about 0 delta. Measured some of my other skis and most were close to 0 delta. So to make a long story short, I made some custom shims for my Chariots to get me to zero delta (raised the toe) and the next time I used them in similar conditions, problem solved. It was amazing how much better they felt. I now make sure all my skis are close to 0 delta. I don't go crazy with this, just want to stay in the same ball park.

One final comment, I am a mechanical design engineer and after becoming aware of delta angle, I looked at the design of my various bindings and my conclusion is the delta is mostly a function of the space needed for the particular ski brake design used. I haven't found a binding with the toe above the heel, and all the heels are made with the minimum space needed to fit the ski brake mechanism under the heel pad. I don't think any "non-race" binding is designed for a particular delta, they just come out how they come out. No manufacturer seems to raise the toe up to meet the heel pad height, you have to do it yourself with a shim. I did see the spec's on the Tyrolia Attack 13 bindings that list a range of delta angles, which is misleading. The AFD raises and lowers to adjust to different toe thickness of different boots, for your boot, there is only one delta, otherwise you will fall out of the binding. (if you want to shim the top of the toe of your boot, you could vary the delta, but that isn't realistic).

I think most skiers never reach the "limit" where delta really smacks you in the face. Not being optimized may reduce your margin for error, somewhat. If your skiing right at your limit all the time, then it is probably wise to optimize it.

 

[Idaho Dan]

I hope no one minds me resurrecting this. If there is a newer thread, please point the way.

I feel like I am in the camp of needing more delta. I have long femurs, short torso, skinny calves, and always feel like I'm in the backseat. My solution now is very flexible boots so that I can flex forward when I bend my knees to remain balanced. I think this comes with major drawbacks though, and is no help at all with my AT boots that I can't make more flexible. Therefore, I want to try to increase my delta.

So my question, if I put a shim underneath my rear bindings, is that going to mess with the safety of the bindings? I'll be changing the delta angle, which will change the angle that the toe fits into the front binding and the angle the heel fits into the rear binding right?

My alpine bindings are Marker Griffons and my AT bindings are Vipec 12s.

Thanks for any input. My local (3 hours away) bootfitter was not a lot of help, so I'm down to tinkering a little myself before I throw in the towel and drive 13 hours to see Bud Heishman.

 

[RuleMiHa]

I hope no one minds me resurrecting this. If there is a newer thread, please point the way.

I feel like I am in the camp of needing more delta. I have long femurs, short torso, skinny calves, and always feel like I'm in the backseat. My solution now is very flexible boots so that I can flex forward when I bend my knees to remain balanced. I think this comes with major drawbacks though, and is no help at all with my AT boots that I can't make more flexible. Therefore, I want to try to increase my delta.

So my question, if I put a shim underneath my rear bindings, is that going to mess with the safety of the bindings? I'll be changing the delta angle, which will change the angle that the toe fits into the front binding and the angle the heel fits into the rear binding right?

My alpine bindings are Marker Griffons and my AT bindings are Vipec 12s.

Thanks for any input. My local (3 hours away) bootfitter was not a lot of help, so I'm down to tinkering a little myself before I throw in the towel and drive 13 hours to see Bud Heishman.

I've come to believe that there are a group of people who are "sensitive to delta", and that it relates strongly to what percentage of your height goes away when your femurs are parallel to the ground. I think that's why there is so much disagreement. People I respect greatly don't feel it but I know what happens to me with minute delta changes and every little thing matters.

As a long femur, short torso, short calf person, I'd suggest just going to see Bud, because sooooo many things can affect fore/aft it's just better to work with someone familiar with the issue.

 

[Philpug]

Actually most bindings now, other than a couple are w/in 1-3mm of flat. The only ones that come to mind that are not, Attack 11, Tyrolia system bindings. Most everyting else is pretty darn near 0*

 

[Mike King]

Adding delta (increasing the height under the heel piece) will actually move you aft on the ski, not forward.

Mike

 

[RuleMiHa]

Adding delta (increasing the height under the heel piece) will actually move you aft on the ski, not forward.

Mike

Not necessarily true. Adding height under the heel piece will tip your skeleton forward. Depending on the situation many people react to that by leaning back, but the intrinsic movement is forward.

I made a ton of adjustments to my delta in small increments, and found the "too much" point where I then lean back and had to back off. So I would say, TOO MUCH DELTA will move you aft on the skis, but the appropriate amount will allow skiers with geometries that tend to put them too aft to be appropriately balanced.

 

[Mike King]

Well, I've seen the effect of putting as little as a quarter under the rear of a ski boot demonstrated by Jim Lindsey, one of the US's most respected boot fitters. It clearly shows that you move back.

Perhaps your anatomy is different, but Lindsey is adamant on the effect (which, as I mentioned, I've personally observed).

Mike

 

[RuleMiHa]

Well, I've seen the effect of putting as little as a quarter under the rear of a ski boot demonstrated by Jim Lindsey, one of the US's most respected boot fitters. It clearly shows that you move back.

Perhaps your anatomy is different, but Lindsey is adamant on the effect (which, as I mentioned, I've personally observed).

Mike

I'm not disagreeing with the observation, but on a baseline level if you tilt something forward it moves forward. If there is a different outcome (moving back) other factors are involved and you can't make a blanket all encompassing statement. Those other factors *need* to be taken into consideration.

The skeletal proportions (and other things) will determine at what level different effects are generated. If someone is standing straight & not allowed to bend or move joints and you put something under his heel he will tilt forward. If he is allowed movement he will straighten himself by opening up the ankle joint. He made a compensatory movement and is standing straight, but that doesn't mean he wasn't tilted forward.

I'm just saying it's the compensatory movements that cause backward movement and they only come into play if you have too much delta. And too much is determined by a skiers individual geometry.

 

[Erik Timmerman]

I hope no one minds me resurrecting this. If there is a newer thread, please point the way.

I feel like I am in the camp of needing more delta. I have long femurs, short torso, skinny calves, and always feel like I'm in the backseat. My solution now is very flexible boots so that I can flex forward when I bend my knees to remain balanced. I think this comes with major drawbacks though, and is no help at all with my AT boots that I can't make more flexible. Therefore, I want to try to increase my delta.

So my question, if I put a shim underneath my rear bindings, is that going to mess with the safety of the bindings? I'll be changing the delta angle, which will change the angle that the toe fits into the front binding and the angle the heel fits into the rear binding right?

My alpine bindings are Marker Griffons and my AT bindings are Vipec 12s.

Thanks for any input. My local (3 hours away) bootfitter was not a lot of help, so I'm down to tinkering a little myself before I throw in the towel and drive 13 hours to see Bud Heishman.

You can lift the heels of those bindings without adversely affecting their function for sure. You will probably want a shop to do this as you may nee longer screws and you aren't going to find those in the hardware store. If it were me, I'd try to experiment with lifting the toe and the heel separately before getting out the post-driver. This wouldn't be Marker approved, but if it were me, I'd stuff an old lifter plate under the toe and then the heel of my binding. Maybe duct-tape it on, and I'd use thin ones 3 maybe 4mm at most and see what it feels like. It is true that most of the time lifting the heel will make it so you feel the front of the ski less, but if you are way, way out then it may work how you are expecting.